The Hard Drive is one of the core hardware components for the computer. It is the component that has Windows 7 stored on it. Windows 7 is an Operating System, which means it operates the system (computer) so that the hardware (i.e Printer) and software (i.e Office) can talk to each other to produce a result (i.e A printed documented).

Fig 1.0  The Hard Drive

Fig 1.1  The needle inside the hard drive reads/writes data

Windows 7 provides a piece of software known as Internet Explorer that allows you to communicate with people over the Internet and view websites. This is made possible because Windows 7 allows a Modem to dial the Internet. Once connected to the Internet it then allows Internet Explorer to see website pages as text and pictures, using different typefaces (fonts) and languages in many cases.

Windows 7 has many other technical jobs to do, but to keep it simple just look at it as the thing that allows you to type letters, view websites, communicate with people, listen to music and so on. There is only one thing to remember about the hard drive and that is that it will not work unless it has an operating system (such as Windows 7) stored on it. If the hard drive gets worn out or damaged Windows 7 will become corrupt and/or unusable. And even if the hard drive is brand new it is still possible to damage/corrupt Windows 7 by deleting its files, catching a virus or what ever - So look after Windows 7 and the hard drive.

When you install Windows 7 it tries to detect the hardware inside the computer. For each piece of hardware it detects (i.e Sound Card) it tries to install its own software for that hardware. If it cannot find any of its own software to install the hardware it will ask you for the CD that came with the hardware, so it can install the software on that CD in order to make the hardware work - So always keep the original CDs. If the hardware did not come with a CD you will need to contact your computer retailer or manufacturer for a replacement CD or get the software from their Internet website if they have one.

Once Windows 7 has been installed, with all your hardware detected and installed, you then install your additional software. Additional software means Office, Anti-Virus, Printer, Scanner, Music, Messenger and so on software. Installing Windows 7, and all the common (additional) software, should take up approximately 13 GigaBytes of hard drive space. This means if you have a 160GB (160 GigaBytes) hard drive you will be left with 147GB for your own use - You could install more additional software like Games, Store your own Folders and Files, Download files from the Internet, Store CD contents and so on.

Each time you go on the internet Windows 7, Internet Explorer and Websites save certain information about you and your activities. For example Windows 7 might save your User Names and Passwords so you do not have to retype them every time you want to go on the internet. Website pages (text and/or pictures) might be saved so that when you want to look at a certain page again it appears instantly, because Internet Explorer will display the saved page first - If the page is updated by the owner Internet Explorer will then download and display the updated page, if it has a connection to the internet. By saving pages it means you can view those pages at your leisure when you are not connected to the internet. And as most pages stay the same (with the same text and pictures on them) the downloading of updated pages is minimal. The saving of information is done for every website you visit.

On top of this Windows 7 is always saving Settings information, Email information, File information and so on. This is necessary to make your experience of the computer faster and better. For example. When you add or delete an email address to/from your contacts list that contacts list needs to be re-saved. Otherwise you would have to manually type in an email address all the time, as opposed to picking it from the saved contacts list. When you update software, like Anti-Virus and Windows 7 software, the updated files have to be saved onto the hard drive as well.

So with forever growing information, installation files and updated files the computer will realistically need 10 GigaBytes of hard drive space - This is a normal scenario for most people. With the remaining space people either leave it empty or use it as storage for their Music files for example. However. As Windows 7 indexes each file it stores on the hard drive, so it can find a file quicker, more hard drive space will be needed for the index itself.

Try to avoid saving redundant files on the hard drive. For example. When you save an installation file, such as a downloaded Game.exe file, onto the hard drive and then install it it will take up additional hard drive space. This is because files that need to be installed have usually been compressed (shrunk). So 10 game files (not 10 games) for example might of been shrunk into 1 small installation (Game.exe) file.

Lets say the 10 game files were 1 MegaByte each (so 10 MegaBytes) and then shrunk into 1 small (3 MegaBytes) installation (Game.exe) file, so it is quicker to download and/or store somewhere. When you activate the small installation file it is expanded back to its original 10 game files, which are then saved inside a Games folder on the hard drive. What this means is you have 10 installed game files and 1 small installation file on the hard drive, so the small installation file is then a redundant file. By saving the small installation file onto CD for example and then activating it from the CD you will save yourself 3 MegaBytes of hard drive space. If you now imagine you had 30 small installation files that would be a saving of 90 MegaBytes, if they were on a CD instead of the hard drive.

If your hard drive is 20 GigaBytes or less it will go round at 5400rpm. And if it is more than 20GB but less than 80GB it will go round at 7200rpm. Larger sized hard drives can go around at 10,000 rpm. A hard drive is like a record player - It spins round and a needle (laser) reads/writes the data (Fig 1.1 above). The faster the rpm the faster the hard drive. If you have an old 5400rpm hard drive it is definitely worth upgrading to a 7200rpm hard drive because the speed difference is noticeable - Data is read/written faster. Two other reasons for upgrading are that it only costs around £50 for a 250GB (laptop) hard drive and because 80GB or less (laptop) hard drives are becoming obsolete. One thing to remember though is that when you buy a new hard drive it is blank - It does not have any software on it at all. Not even Windows 7.

In terms of hard drive size, although 1 GigaByte is 1,024,000,000 Bytes, you have to look at the size of the average file these days to put hard drive size into perspective. Here are some figures based on a 40 GigaByte hard drive:

Although in reality you will never use the whole 40GB, never say never. With music downloading, digital cameras, scanners and bigger files becoming standard the need for storage space will grow. Hence why many laptops for example come with a 160GB hard drive as standard. So multiply the figures above by 4 to see what you can put on that 160GB hard drive.

When a computer and its hard drive are new you hear nothing but the fan inside the computer. A humming sound. As the hard drive gets older it starts to make a light jingling/drumming sound that overtakes the sound of the fan. Nothing serious, perhaps a few decibels only. And when the hard drive is really old it makes a noticable, loudish, screeching/drumming/tapping sound. This is when it is time to replace the hard drive.

As a rule, try and replace the hard drive every 3 or 4 years (5 Maximum) if the hard drive is 80GB or more. If it is less than 80GB it should be in the dustbin already. By not replacing the hard drive you risk losing/damaging your files due to the hard drive's age (Corruption, Unable to read/write data and so on). Also backup (save) your files onto floppy disks or CDs every month or so, regardless if the hard drive is new or old.

Microsoft product screen shot(s) reprinted with permission from Microsoft Corporation.  As stated here by the Microsoft Corporation.